1. Field of the Invention
This invention relates to a device for controlling the temperature and the humidity of an environmental testing chamber in which to conduct various tests on a self-propelled vehicle, such as an automobile.
2. Description of the Prior Art
As one of performance test itmes for a self-propelled vehicle, such as an automobile, a series of tests are conducted on the vehicle under assumed constant temperature and humidity air conditions.
The air or wind supplied into the testing chamber of this testing device has an extremely low latent heat load, although it has a larger air or wind volume or capacity and a significant sensible heat load.
In the conventional devices, excess cooling and reheating are required for eliminating the latent heat load under conditions of the higher temperature and lower humidity, while a larger cross-sectional area of the wind channel of the air conditioning unit is used for lowering the wind velocity and thereby preventing splashing of condensed water.
Thus the conventional device is formed by a large-sized air conditioning unit and an amount of the thermal medium that is several times that corresponding to the actual load operation.
In addition, fluctuations are caused in the outlet air temperature of the air conditioning unit of the conventional control device with concomitant temperature fluctuations on the overall operating area of the air conditining unit of the conventional control device due to changes in the thermal medium in the course of the temperature control operation.
In addition, since the control device of the type described above has a wind tunnel system, temperature fluctuations will occur at the air diffuser opening or supply opening as a direct consequence of the temperature fluctuations at the outlet of the air conditioning unit, thus interfering with various tests to be conducted on the self-propelled vehicles.